1. Field of the Invention
The invention is based on a post insulator.
2. Discussion of Background
An insulator having an insulator body is known from European Patent Specification 0,288,715 B1. The insulator body can be subjected to a pressure medium. Insulant gases such as, for example, SF.sub.6 or else mineral oil may be envisaged as the pressure medium. In addition, the insulator could even be subjected to a vacuum. The insulator body consists of a cured cast resin. A potted fitting which contains a metallic support body passes through the insulator body. During operation, the potted fitting is subjected to high voltage. The support body has a lateral surface which is provided with a coupling layer which is applied in a manner which is leaktight with respect to the pressure medium and is designed to be elastic. The insulator body is encapsulated with this elastic coupling layer.
Elastically designed coupling layers of this type are well-suited for insulators with comparatively low mechanical loading. For more modern systems, in which the insulators are loaded to ever-increasing levels, elastic coupling layers of this kind are no longer suitable, since better adhesion between the lateral surface of the support body and the insulator body is demanded.